1. Field of the Invention
This invention relates to a pressure-sensitive adhesion-processed sheet to be used in stickers, labels and so on.
2. Background of the Invention
Existing pressure-sensitive adhesion-processed sheets comprise a pressure-sensitive adhesion-processed sheet constructed by forming a flat pressure-sensitive adhesive layer on a sheet base material and a release sheet bonded to the flat pressure-sensitive adhesive layer. In use, the release sheet, which usually has a flat releasing-treated face, is peeled off and the pressure-sensitive adhesive layer of the pressure-sensitive adhesion-processed sheet is stuck to an adherend.
These pressure-sensitive adhesion-processed sheets frequently suffer from such a problem that air is entrapped between a pressure-sensitive adhesion-processed sheet and an adherend and then blisters are formed due to the entrapped air. After sticking, therefore, convexities are formed on the front face of the pressure-sensitive adhesion-processed sheet and its appearance is seriously damaged. This problem is particularly serious in the case of using a large-sized pressure-sensitive adhesion-processed sheet or an adherend having a smooth surface.
In the case of using a plastic adherend (for example, polycarbonate resin, acrylic resin, foamed polystyrene resin or the like), it is sometimes observed that a gas is generated from the plastic surface with the passage of time so that blusters are formed on the pressure-sensitive adhesion-processed sheet.
To overcome the above-described problems, various pressure-sensitive adhesion-processed sheets have been proposed by Japanese Utility Model Registration No.2503717, JP-A-3-243677 and so on. However, these techniques are poor in productivity and yet expensive compared with the existing pressure-sensitive adhesion-processed sheets.